They live for books. Books are truth: word of the Lord. Adso knows this in his soul, feels it in his bones where he sits in the Aedificium, curled over his desk: workplace dimly lit by deep-set windows.
But today he's visiting the Balneary and it makes him think of the sea, which he has never seen. Their Library knows the marvels of the world though, so he's pleasing himself dreaming a seagull.